How long has it been out of the freezer? If it was in there overnight or something, I'd say throw it away. I haven't had to refreeze yet, so I don't know, but I think some people have said you can put it back in the freezer once and then thaw it again later, but if he still doesn't eat it a second time, throw it away. Others can clarify that though.

Jojo's probably still healing, right? Give him more time, I'm sure he'll eat for you again.